Adenosine triphosphate (ATP) levels are recognized as a critical indicator of microbial content in food safety. The development of highly efficient ATP-sensing methods is essential for assessing food freshness. Herein, we propose a simple-yet-efficient hemin/G-quadruplex (G4) DNAzyme-based aptasensor for ATP detection and oyster freshness assessment. The anti-ATP aptamer subunits specifically bind to ATP, leading to self-assembly of the hemin/G4 DNAzyme. The newly produced DNAzyme then catalyzes the oxidation of ABTS 2- to produce the colored ABTS •− , providing an absorbance response for sensitive ATP analysis. The aptasensor facilitates high-performance and accurate determination of ATP with a low detection limit of 0.065 μM. Furthermore, this sensor enables reliable ATP analysis in oyster samples and evaluation of oyster freshness. In particular, a good linear correlation was established between microbial content and ATP levels. The proposed aptasensor for the assessment of freshness is characterized by its simplicity and efficiency, potentially offering a new tool to monitor food safety.
Jie Wei,Yumeng Li,Qingyang Si,Qiao Xiao,Qingmin Chen,Tianhui Jiao,Quansheng Chen,Xiaomei Chen
A label-free, sensitive and reliable electrochemical sensor based on hemin/G-quadruplex (G4) DNAzyme was engineered to determine adenosine triphosphate (ATP) in fish. The nucleic acid sequence (DNA1) including the G4 sequence subunit and anti-ATP aptamer segment is anchored on Au electrodes. The nucleic acid sequence (DNA2) is composed of another G4 sequence fragment and anti-ATP aptamer subunit. The probes DNA1 and DNA2 self-assemble into the active hemin/G4 DNAzyme structure on Au electrodes upon exposure to the target ATP. The determination of the target ATP relied on an increase in the catalytic currents occurring on DNAzyme-anchored electrode via the electrochemical reduction of H 2 O 2 . The proposed strategy enables high-performance and specified determination of the target ATP with a detection limit of 0.04 μmol/L. Specifically, the proposed ATP strategy was further implemented to determine ATP in microorganisms in carp samples. Compared with the classical total viable count (TVC) assay, the proposed ATP assay was feasible to assess the freshness of carp, which expands the applications of hemin/G4 DNAzyme and holds promising potential for freshness assessment in food safety.
危险品化学品经营许可证（带存储）